package dome;

import java.util.Stack;

class MyQueue {
     private Stack<Integer> s1;
    private Stack<Integer> s2;

        public MyQueue() {
              s1 = new Stack<>();
              s2 = new Stack<>();
        }

        public void push(int x) {
             s1.push(x);
        }

        public int pop() {
               if (s1.empty()){
                   return  -1;
               }
               if(s2.empty()){
                   while (!s1.empty()) {
                       s2.push(s1.pop());
                   }
               }
               return s2.pop();
        }

        public int peek() {
            if (s1.empty()){
                return  -1;
            }
            if(s2.empty()){
                while (!s1.empty()) {
                    s2.push(s1.pop());
                }
            }
            return s2.peek();
        }

        public boolean empty() {
         return  s1.empty()&&s2.empty();
        }

}
